Regarding Kane’s return around Royal Rumble time, it’s not yet known if he will be wearing the mask upon his return. Many backstage believe that the decision is very much still up in the air. The reason the mask has been used in the adverts promoting his return is because the company wanted no doubt in who they were promoting to return as they are also playing the cryptic 1/2/12 vignettes and that’s where they want their fans to be guessing.
As for his return, it’s expected that he will be returning to the company as a heel. He has been out of action since the July 22, 2011 edition of SmackDown! where he was “injured” at the hands of Mark Henry. WWE reported at the time that Kane suffered a fractured fibula and would be returning within 3-4 months.